The present invention relates to a corrosion protective lacquer for braking surfaces of brake disks and/or brake drums, a corrosion protective coating made thereof, and a method for removing the corrosion protective coating as it is used in the shop of the applicant.
For protection from corrosion, a brake disk and/or brake drum is generally lacquered. For this a lacquer is used which can be removed by braking, that is, removed by the abrasive action of the brake pad in the area of the braking surface. This solution has proven particularly favorable in vehicles designated for overseas transportation and with replacement brake disks or drums.
Despite the advantages of convention methods, braking surfaces of brake disks or braking surfaces treated with it still demonstrate sensitivities during transportation, especially because of the aggressive salt air during overseas transportation. High quality assurance costs and partial reworks are connected with this.
It is an object of the present invention to provide a corrosion protective lacquer with which a corrosion protective coating may be produced which makes possible a corrosion protection even in overseas transportation, less rework and cost reduction, and which may be removed as simply as possible.
The above and other beneficial objects of the present invention are achieved by providing a corrosion protective lacquer, a corrosion protective coating and a method as described herein. Access of oxygen to the braking surface is prevented by covering at least the braking surfaces with a corrosion protective lacquer according to the present invention having a high proportion of protective substances that react with oxygen.
In order to achieve the desired effect, a protective substance proportion of at least 30% by volume, for example, at least 50% by volume or at least 70% by volume, is practical in the lacquer or clearcoat that is otherwise, for example, of customary type.
These protective substances may include, for example, non-alkaline and non-earth alkaline metals such as, for example, zinc, elemental aluminum or their oxidizable compounds, such as, for example, FeO. Additionally, phosphorus and/or phosphates are also suitable.
During removal by braking, the substances are, at least partially, for example, pressed and/or rubbed into the surface of the braking surface, where they remain and further effect protection of the metallic surface from oxidation. This removal by braking may be performed at any time, for example, however, before delivery of an automobile to a customer, such as on a roller test stand. Because one obtains corrosion protective action even after the removal of the corrosion protective coating by braking, the removal of the corrosion protective coating may be performed, for example, before mounting the brake disk, shortly after its manufacture, so that only a brake disk is mounted that is ready and protected from corrosion.
By the introduction of the protective substances into the surface rough spots, pores and score marks of the braking surface, the normal surface roughness of the braking surfaces, which results due to the natural pores of the brake disk material and/or grinding or turning score marks, is reduced at the same time. The result is a lesser depth of corrosion, whereby in turn the probability of brake judder is lessened at the same time.
In order to achieve a particularly satisfactory result, the average particle size of the protective substances may be smaller than the maximum roughness and/or the average pore width and/or the average score mark size of the braking surface.
A metal lacquer having a zinc dust proportion of approximately 80% by volume may be a cost-effective solution.